In a fresh hearing pertaining to noise and air pollution both in the vicinity of Indira Gandhi International Airport (IGIA), National Green Tribunal (NGT) directed Airport Authority of India (AAI) and Delhi International Airport Limited (DIAL) to submit "factual and action taken" report within a month. 

Notably, NGT ordered DIAL to initiate steps to curb noise pollution in residential areas near airports so that people are not disturbed.

This may be recalled, following the petition, the Centre had informed the High Court that the IIT - Delhi and experts  have been asked to evolve a mechanism to curtail noise pollution near the airport. It was way back in 2010, DIAL had roped in IIT-Delhi to suggest sound barrier designs. Later all such petitions were transferred to the NGT.

A South Delhi resident had again submitted a petition to Ministry of Environment and Forest (MoEF) on January 25, 2016 saying DIAL has failed to install any noise barrier on the south side of runway 29/11.

IIT-Delhi and experts were supposed to complete the project in three months. However, even after eight years, IIT report has not been made public or submitted to the court.

Importantly, as per the sources, IIT Mechanical Engineering Department that had conducted the study, had informed the DIAL that a continuous sound barrier could be built on the south side of the runway as done in many airports across the world. According to the report, the navigation aids could easily be raised or moved to the north side of the runway.